Using dllexport on a function with the __clrcall convention

[tobyjug]

Using dllexport on a function with the __clrcall convention

Hi there, I'm pretty new to using C++ after using C# for a while now and so the syntax and that is pretty similar...
Anyway what I am trying to do is make a DLL in C++ that will interact with the Ultima.dll. I want to do this because I am writing a form that runs from within the runuo server and so it is impossible to add Ultima.dll as a reference and Ultima.dll doesn't export it's functions so I can't use dllimport in my C# code of my form. So basically I'm writing my C++ DLL that has a reference to Ultima.dll in it and then I am writing functions in my C++ dll to export bitmaps created using the functions from Ultima.dll.
However I'm having a problem with exporting my functions from my C++ dll because of the following error:

error C3395: 'UltimaHelper::Gumps::GetGump' : __declspec(dllexport) cannot be applied to a function with the __clrcall calling convention

Here is my UltimaHelper.dll code in C++:

#pragma once
using namespace System;
using namespace Ultima;

namespace UltimaHelper 
{
    public class __declspec(dllexport) Gumps
    {
        public: static System::Drawing::Bitmap^  GetGump(int index)
        {
            System::Drawing::Bitmap^ returnImage = Ultima::Gumps::GetGump(index);
            return returnImage;
        }

    };
}

Thanks for any help

 

[arul]

C++ projects compiled with /clr parameter are compiled into IL, and thus you can use them within your managed project with no problem.

__declspec may be used only if you compile into native code, which can be achieved through some #pragma macro.

 

[tobyjug]

Ok, so if you dont mind me asking some further questions...
What is a Pragma macro? What would one look like for me to be able to export my function?

 

[arul]

There's a nice article about it over at CodeProject.

http://www.codeproject.com/dotnet/managed_unmanaged.asp